The present disclosure relates to an optical scanning device and an image forming apparatus including the optical scanning device.
In a known optical scanning device used in an electrophotographic image forming apparatus such as a laser printer, laser light emitted by a light source is reflected and deflected by a rapidly rotating polygon mirror. The laser light having been reflected by the polygon minor passes through an optical lens and then scans the surface of a photoconductive drum.
This optical scanning device includes a polygon motor, a driver IC and a substrate. The polygon motor drives and rotates the polygon minor. The driver IC is an IC (Integrated Circuit) for driving the polygon motor. On the substrate, the driver IC is mounted, and a bearing hole for catching the rotating shaft of the polygon motor is formed.
In this optical scanning device, if the polygon motor is operated at a high speed, heat generated from the driver IC becomes so excessively large that the optical lens may be thermally deformed, which leads to a problem of quality degradation of a printed image.
On the contrary, in another optical scanning device, an elastic heat transfer member is sandwiched between a substrate and a heat releasing member. Thus, the substrate is in contact with the heat releasing member via the heat transfer member. Accordingly, heat generated from a driver IC is rapidly transferred from the substrate through the heat transfer member to the heat releasing member.
In still another optical scanning device, an end portion of a metal cover housing a polygon mirror and a substrate is in direct contact with a driver IC. Thus, the metal cover can be used as a heat releasing member.